feat(common): implement DumbAware interface in AbstractFileIconProvider

- Make AbstractFileIconProvider DumbAware to prevent issues during indexing.
- Ensure consistent formatting in README.md.
- Add YourKit sponsorship acknowledgment in README.md.

README.md

@@ -114,8 +114,6 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
 This project follows the [all-contributors](https://github.com/all-contributors/all-contributors) specification.
 Contributions of any kind welcome!
 
-image::https://www.yourkit.com/images/yklogo.png
-
 ![YourKit](https://www.yourkit.com/images/yklogo.png)
 
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